What is the common intracellular concentration of hydrogen phosphate ions (HPO4--) in mEq/L?

The common intracellular concentration of hydrogen phosphate ions (HPO4--) is approximately 75 mEq/L. This concentration is significant for maintaining the proper physiological balance within cells. Hydrogen phosphate plays a critical role in intracellular buffering systems, as it can accept or donate protons (H+) depending on the pH of the cellular environment. This ability to buffer helps to stabilize the pH, which is essential for various biochemical reactions and overall cellular function.

In addition to its role in pH regulation, HPO4-- is also involved in energy metabolism, particularly as a component of adenosine triphosphate (ATP), which is fundamental to energy transfer in cells. Understanding the normal range of HPO4-- concentration is vital for healthcare professionals, as alterations in this level can indicate underlying health issues, such as metabolic or respiratory disorders.

The other concentrations provided do not accurately reflect the typical intracellular levels of hydrogen phosphate and would not represent the physiological conditions found in human cells.